Characterization of YBCO bulk superconductors for 100 kW h flywheel

K. Matsunaga, N. Yamachi, M. Tomita, Masato Murakami, N. Koshizuka

Research output: Contribution to journalArticle

10 Citations (Scopus)


We characterized YBCO bulk superconductors that will be installed in the radial type superconducting magnetic bearing module for a 100 kWh class flywheel system. The inner-stator is a cylinder with the outer diameter of 208 mm, the inner diameter of 180 mm, and the height of 100 mm. At present the stator is planned to consist of 24 and 16 YBCO plates. We measured the trapped magnetic-field distribution of the YBCO plates that will be installed in the stator by using Hall probes at 77 K after having been cooled in the presence of 1.5 T. The peak field values ranged from 0.82 to 0.87 T. The field distribution suggested that the YBCO plates were almost single domain. We also measured the repulsive force between the YBCO bulk at 77 K and a permanent magnet with the magnetic surface induction of 0.37 T. The repulsive force was about 50 N at 1.5 mm gap.

Original languageEnglish
Pages (from-to)723-728
Number of pages6
JournalPhysica C: Superconductivity and its Applications
Issue numberPART 1
Publication statusPublished - 2003 Oct
Externally publishedYes



  • Repulsive force
  • Superconducting magnetic bearing
  • Trapped magnetic-field
  • YBCO bulk superconductor

ASJC Scopus subject areas

  • Condensed Matter Physics

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